A horrendous terrorist attack has struck the U.S., and all clues point to an Atlantean sleeper cell. Now, Namor finds himself in S.H.I.E.L.D.'s crosshairs. But is Namor to blame? Or is this merely the first strike orchestrated by those within Atlantis who would see Namor stripped of his title and his kingdom? The half-human, half-Atlantean son of two worlds must race between the sea and the surface to track down those responsible for the attack before Tony Stark, Director of S.H.I.E.L.D. - a.k.a. Iron Man - takes him down.